export interface Card {
  id: string;
  front: string;
  back: string;
  deckId: string;
  nextReviewDate?: Date;
  ease: number; // 难度系数
  interval: number; // 复习间隔（天）
  repetitions: number; // 重复次数
  lastReviewed?: Date;
}

export interface Deck {
  id: string;
  name: string;
  description?: string;
  cards: Card[];
  createdAt: Date;
  updatedAt: Date;
}

export enum ReviewRating {
  Again = 1,
  Hard = 2,
  Good = 3,
  Easy = 4,
}

export interface ReviewStats {
  totalCards: number;
  newCards: number;
  reviewCards: number;
  masteredCards: number;
}
